The present invention relates to the art of foundry, and more specifically to an installation for producing bimetallic solid bodies of cylindrical shape by pouring molten metals into a rotary casting mould.
The most successful use of the invention can be made in the production of mill rolls featuring high hardness and wear resistance.
No less advantageously can this invention be employed for making flour milling rolls, rolls for the chemical, paint and lacquer, and other industries.
Most generally used in installations for manufacturing hollow bimetallic bodies of cylindrical shape are casting molds having a horizontal axis of rotation. Production of solid bodies involves a problem of preventing the outflow of fluid metal from the casting mould when the central zone of the mould is being filled by the fluid metal.
Known in the art are attempts to seal the clearance between the casting mould and an immovable runner means adjoining it, by means of a gland filled with fluid lead and mounted at the end of the mould. (see, for example Soviet journal "Litsynoyo Delo" No. 10, 1934).
However, these attempts were unsuccessful due to the difficulty of supplying fluid lead into a rotating gland.
Also known are attempts related to the method of pouring a first metal into the mould rotating about its horizontal axis, a second metal being poured into the casting mould only after mounting it in a vertical position (see, for example, Japanese Pat. Nos. 35-5618 dated 1960, and No. 39-11205 dated 1964).
However, when pouring metal into a vertically disposed mould, there emerge difficulties connected with the retention of a layer of flux intended to protect the surface of the first metal layer against oxidation, as well as difficulties connected with the observed nonuniform distribution of temperature throughout the depth of the mould. Yet the uniform distribution of both the flux layer and temperature are the decisive conditions affecting the structural uniformity, density, and reliability of the joint of metals. Also, the installation turns out to be rather complex, which is due to the need for shifting the casting mould from a horizontal into a vertical position and back within extremely small time intervals determined by the heat transfer conditions. This problem is most acute for installations intended to produce large castings.
Another problem connected with the casting mould whose position must be changed before pouring the second metal, consists in the need to have a head, the weight of which exceeds the weight of metal of the casting by a factor of 1.5-2.0 times.